Statistical characteristics of the thermal conductivity of frozen clay at different water contents

• Published in: Results in physics Vol. 13; p. 102179
• Main Authors: Li, Shuangyang, Wang, Chong, Shi, Lianghong, Yin, Nan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2019; Elsevier
• Subjects: Frozen clay; Gamma distribution; Lognormal distribution; Normal distribution; Statistical characteristic; Thermal conductivity; Gamma distribution; Thermal conductivity; Statistical characteristic; Frozen clay; Normal distribution; Lognormal distribution
• ISSN: 2211-3797; 2211-3797
• DOI: 10.1016/j.rinp.2019.102179

Over 50% of the global land area suffers cyclic freeze-thaw actions, resulting in extensive distribution of frozen soil. Frozen soil contains lenses of ice, and thus, it exhibits temperature-related properties and behaviors. The thermal conductivity of frozen soil is a key property and an essential parameter for performing thermal analyses on frozen soil. However, the thermal conductivity is variable and cannot be determined accurately based on small-scale specimen tests because no frozen soil specimens are identical in nature. Thus, little is known about the variability and statistical characteristics of frozen soil. To address this lack of knowledge, we conducted large-scale tests on numerous samples (≥50 specimens under each set of conditions) and measured the thermal conductivities of frozen clay from the Qinghai-Tibet Plateau (QTP) at 3 water contents (10%, 14% and 18%). The measured data show that the thermal conductivities of the 50 clay specimens differ remarkably and exhibit obvious variability, even at the same soil temperature. Next, we selected 4 potential probability distributions for comparison with the measured curves. The normal distribution, lognormal distribution and gamma distribution all demonstrate good agreement with the measured data and support the hypothesis. Based on goodness-of-fit analysis, we recommend using a normal distribution to describe the thermal conductivity of frozen clay. The measured data and conclusions provide a theoretical basis and reference for thermal analyses on cold regions engineering.